public static int Parse(int helperPid, File file, Process proc, ref UserPtr stackTop)
{
Contract.Requires(file.GhostOwner == proc);
Contract.Requires(proc.Space.GhostOwner == proc);
var buf = new byte[Size];
uint pos = 0;
if (file.Read(buf, ref pos) != buf.Length)
return -ErrorCode.EINVAL;
var eh = Read(buf);
if (eh.type != ELF32Header.ELF_TYPE_EXECUTABLE || eh.ProgramHeaderOffest == 0)
return -ErrorCode.ENOEXEC;
proc.EntryPoint = eh.EntryPoint;
ELF32ProgramHeader ph = new ELF32ProgramHeader();
var ret = FindInterpreter(file, eh, ref ph);
if (ret == -ErrorCode.EINVAL)
{
Arch.Console.WriteLine("Malformed ELF file");
return ret;
}
else if (ret == 0)
{
var interpreterBuf = new byte[ph.FileSize];
pos = ph.offset;
if (file.Read(interpreterBuf, ref pos) != interpreterBuf.Length)
return -ErrorCode.EINVAL;
var interpreterName = new ASCIIString(interpreterBuf);
ErrorCode ec;
var interpreter_inode = Arch.ArchFS.Open(helperPid, interpreterName, 0, 0, out ec);
if (interpreter_inode == null)
return -ErrorCode.ENOENT;
var interpreter = new File(proc, interpreter_inode, FileFlags.ReadOnly, 0);
/*
* Parse the information of linker.
*
* This function will also override the entry point.
*/
if (Parse(helperPid, interpreter, proc, ref stackTop) != 0)
return -ErrorCode.EINVAL;
// So now let's copy the program header to the top of the stack, and push auxlirary vectors
PushProgramHeaderAndAuxliraryVectors(proc, file, eh, ref stackTop);
}
return MapInSegments(file, proc, eh);
}
private static int PushProgramHeaderAndAuxliraryVectors(Process proc, File file, ELF32Header eh, ref UserPtr stackTop)
{
var programHeaderLength = eh.NumOfProgramHeader * eh.ProgramHeaderSize;
var buf = new byte[programHeaderLength];
uint pos = eh.ProgramHeaderOffest;
if (file.Read(buf, ref pos) != programHeaderLength)
{
return(-ErrorCode.ENOMEM);
}
stackTop -= programHeaderLength;
UserPtr ph_ptr = stackTop;
if (ph_ptr.Write(proc, buf) != 0)
{
return(-ErrorCode.ENOMEM);
}
// align
stackTop = UserPtr.RoundDown(stackTop);
var aux_vector = new uint[LengthOfAuxVector];
aux_vector[0] = AT_PHDR;
aux_vector[1] = ph_ptr.Value.ToUInt32();
aux_vector[2] = AT_ENTRY;
aux_vector[3] = eh.EntryPoint;
aux_vector[4] = AT_PHNUM;
aux_vector[5] = eh.NumOfProgramHeader;
aux_vector[6] = 0;
aux_vector[7] = 0;
var auxVectorSize = sizeof(uint) * LengthOfAuxVector;
stackTop -= auxVectorSize;
if (stackTop.Write(proc, aux_vector) != 0)
{
return(-ErrorCode.ENOMEM);
}
return(0);
}
private static int FindInterpreter(File file, ELF32Header eh, ref ELF32ProgramHeader ret)
{
var buf = new byte[ELF32ProgramHeader.Size];
uint pos = 0;
ushort i = 0;
while (i < eh.NumOfProgramHeader)
{
pos = (uint)(eh.ProgramHeaderOffest + eh.ProgramHeaderSize * i);
if (file.Read(buf, ref pos) != ELF32ProgramHeader.Size)
return -ErrorCode.EINVAL;
ret = ELF32ProgramHeader.Read(buf);
if (ret.type == ELF32ProgramHeader.PT_INTERP)
break;
++i;
}
return i == eh.NumOfProgramHeader ? -ErrorCode.ENOENT : 0;
}
private static int PushProgramHeaderAndAuxliraryVectors(Process proc, File file, ELF32Header eh, ref UserPtr stackTop)
{
var programHeaderLength = eh.NumOfProgramHeader * eh.ProgramHeaderSize;
var buf = new byte[programHeaderLength];
uint pos = eh.ProgramHeaderOffest;
if (file.Read(buf, ref pos) != programHeaderLength)
return -ErrorCode.ENOMEM;
stackTop -= programHeaderLength;
UserPtr ph_ptr = stackTop;
if (ph_ptr.Write(proc, buf) != 0)
return -ErrorCode.ENOMEM;
// align
stackTop = UserPtr.RoundDown(stackTop);
var aux_vector = new uint[LengthOfAuxVector];
aux_vector[0] = AT_PHDR;
aux_vector[1] = ph_ptr.Value.ToUInt32();
aux_vector[2] = AT_ENTRY;
aux_vector[3] = eh.EntryPoint;
aux_vector[4] = AT_PHNUM;
aux_vector[5] = eh.NumOfProgramHeader;
aux_vector[6] = 0;
aux_vector[7] = 0;
var auxVectorSize = sizeof(uint) * LengthOfAuxVector;
stackTop -= auxVectorSize;
if (stackTop.Write(proc, aux_vector) != 0)
return -ErrorCode.ENOMEM;
return 0;
}
private static int MapInSegments(File file, Process proc, ELF32Header eh)
{
Contract.Requires(file != null && file.GhostOwner == proc);
Contract.Requires(proc.Space.GhostOwner == proc);
var buf = new byte[ELF32ProgramHeader.Size];
var ph = new ELF32ProgramHeader();
// At this point we need to map in all stuff in PT_LOAD
for (var i = 0; i < eh.NumOfProgramHeader; ++i)
{
var pos = (uint)(eh.ProgramHeaderOffest + eh.ProgramHeaderSize * i);
if (file.Read(buf, ref pos) != buf.Length)
return -ErrorCode.EINVAL;
ph = ELF32ProgramHeader.Read(buf);
var size = ph.FileSize > ph.MemorySize ? ph.FileSize : ph.MemorySize;
if (ph.type != ELF32ProgramHeader.PT_LOAD)
continue;
// Round address to page boundary
var diff = Arch.ArchDefinition.PageOffset(ph.vaddr);
var vaddr = new Pointer(ph.vaddr);
var offset = ph.offset;
var memSize = (int)Arch.ArchDefinition.PageAlign((uint)ph.MemorySize);
var fileSize = ph.FileSize;
if (diff < 0 || ph.offset < diff || fileSize + diff > file.inode.Size || fileSize <= 0 || memSize <= 0)
return -ErrorCode.EINVAL;
vaddr -= diff;
offset -= (uint)diff;
fileSize += diff;
if (fileSize > memSize)
fileSize = memSize;
if (proc.Space.AddMapping(ph.ExpressOSAccessFlag, 0, file, offset, fileSize, vaddr, memSize) != 0)
return -ErrorCode.ENOMEM;
// Update brk
var segmentEnd = (vaddr + memSize).ToUInt32();
if (segmentEnd > proc.Space.Brk)
{
proc.Space.InitializeBrk(segmentEnd);
}
}
return 0;
}
public static int Parse(int helperPid, File file, Process proc, ref UserPtr stackTop)
{
Contract.Requires(file.GhostOwner == proc);
Contract.Requires(proc.Space.GhostOwner == proc);
var buf = new byte[Size];
uint pos = 0;
if (file.Read(buf, ref pos) != buf.Length)
{
return(-ErrorCode.EINVAL);
}
var eh = Read(buf);
if (eh.type != ELF32Header.ELF_TYPE_EXECUTABLE || eh.ProgramHeaderOffest == 0)
{
return(-ErrorCode.ENOEXEC);
}
proc.EntryPoint = eh.EntryPoint;
ELF32ProgramHeader ph = new ELF32ProgramHeader();
var ret = FindInterpreter(file, eh, ref ph);
if (ret == -ErrorCode.EINVAL)
{
Arch.Console.WriteLine("Malformed ELF file");
return(ret);
}
else if (ret == 0)
{
var interpreterBuf = new byte[ph.FileSize];
pos = ph.offset;
if (file.Read(interpreterBuf, ref pos) != interpreterBuf.Length)
{
return(-ErrorCode.EINVAL);
}
var interpreterName = new ASCIIString(interpreterBuf);
ErrorCode ec;
var interpreter_inode = Arch.ArchFS.Open(helperPid, interpreterName, 0, 0, out ec);
if (interpreter_inode == null)
{
return(-ErrorCode.ENOENT);
}
var interpreter = new File(proc, interpreter_inode, FileFlags.ReadOnly, 0);
/*
* Parse the information of linker.
*
* This function will also override the entry point.
*/
if (Parse(helperPid, interpreter, proc, ref stackTop) != 0)
{
return(-ErrorCode.EINVAL);
}
// So now let's copy the program header to the top of the stack, and push auxlirary vectors
PushProgramHeaderAndAuxliraryVectors(proc, file, eh, ref stackTop);
}
return(MapInSegments(file, proc, eh));
}
private static int MapInSegments(File file, Process proc, ELF32Header eh)
{
Contract.Requires(file != null && file.GhostOwner == proc);
Contract.Requires(proc.Space.GhostOwner == proc);
var buf = new byte[ELF32ProgramHeader.Size];
var ph = new ELF32ProgramHeader();
// At this point we need to map in all stuff in PT_LOAD
for (var i = 0; i < eh.NumOfProgramHeader; ++i)
{
var pos = (uint)(eh.ProgramHeaderOffest + eh.ProgramHeaderSize * i);
if (file.Read(buf, ref pos) != buf.Length)
{
return(-ErrorCode.EINVAL);
}
ph = ELF32ProgramHeader.Read(buf);
var size = ph.FileSize > ph.MemorySize ? ph.FileSize : ph.MemorySize;
if (ph.type != ELF32ProgramHeader.PT_LOAD)
{
continue;
}
// Round address to page boundary
var diff = Arch.ArchDefinition.PageOffset(ph.vaddr);
var vaddr = new Pointer(ph.vaddr);
var offset = ph.offset;
var memSize = (int)Arch.ArchDefinition.PageAlign((uint)ph.MemorySize);
var fileSize = ph.FileSize;
if (diff < 0 || ph.offset < diff || fileSize + diff > file.inode.Size || fileSize <= 0 || memSize <= 0)
{
return(-ErrorCode.EINVAL);
}
vaddr -= diff;
offset -= (uint)diff;
fileSize += diff;
if (fileSize > memSize)
{
fileSize = memSize;
}
if (proc.Space.AddMapping(ph.ExpressOSAccessFlag, 0, file, offset, fileSize, vaddr, memSize) != 0)
{
return(-ErrorCode.ENOMEM);
}
// Update brk
var segmentEnd = (vaddr + memSize).ToUInt32();
if (segmentEnd > proc.Space.Brk)
{
proc.Space.InitializeBrk(segmentEnd);
}
}
return(0);
}
